APPLICANT'S ABSTRACT: The Alcopatch is a new test for alcohol consumption which operates by transdermal dosimetry. It is worn as an adhesive wristband and collects ethanol excreted from the surface of the skin after any alcoholic beverages are consumed. The amount of ethanol measured in the Alcopatch varies with the quantity which has been consumed. The Alcopatch is a fourth- generation device which incorporates protection against sample loss and tampering. The object of this research is to calibrate the performance of the Alcopatch in 10 moderate drinkers over eight days, while monitoring their alcohol consumption with self-reports and a portable electronic recording dosimeter during the same period.